Signaling system



R. S. WILBUR SIGNALING SYSTEM Dec. 8, 1925. I 1,565,131

Filed July 2, 1921 I S I Q Bay .5 W/Xur:

telegraph im ulses, there occur in the line tion.

Patented D... e, 1925.

UNITED STATES PAT- any s. WILBUR, or LYNDI'IURST, NEW

l 1,565,131 ENT" OFFICE.

COMPANY, INCORPORATED, OE NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SIGNALING SYSTEM.

Application filed July 2,

To all whom it may concern:

' Be it known that I,'RAY S. WILBUE, a citizfen of the. United States of America, residing at Lyndhurst, in the county of Bergen, State of New Jersey, have invented certain new and useful Improvements 'in Signaling Systems; of which the following is a full,'clear, concise, and exactdescrip- This invention relates to repeating systems and more articularly it relates to composite four-wlre re eater circuits.

Oneof the objects 0 thisinvention is to amplification or repeating of the different types of signals employed in a. signaling system. i

In composite repeater, systems wherein the sides of the telephone line are employed also for the transmissionof the three typesov signals, the telephone si naling currents, the telegraph currents an the ringing currents. In such a system it is frequently desirable to avoidthe passage and consequent amplification of the telegraph currents through the telephone repeaters, since it, has been found that the telegraph signals cause disturbances in and affect the transmitting qualities of the talking circuit ,if they are so amplified. In accordance "withthis invention, the selective amplification of these signals of different types is accomplished, in the case where it is desired to amplify the ringing currents by the telephone repeater while not impressing thereon the telegraph signals, by providing a wave filter in front of the repeater so designed so as to suppress all frequencies below the range of importance in speech. The telegraph signals I are transmitted around the filter and the .repeater through a by-path containing choke coils for preventing eech -.currents from being transmitted t ereringing currents by the same ampli speech. currents, this difficulty may come-by providing a suitable path around through. Such an arrangement, while securing the roper difl erentiation between the telegrap and the telephone currents, does not provide for the transmission of the ringing currents through or around the repea-ter. In case it is desired to amfiplify the er as the be overthe filter, which path by means of an antiresonant circuit will transmit therethrough 1921. Serial Iva-482,011.

the ringing frequency currents,.while suppressing the-transmission of the telegraph currents.

This invention will be better understood,

by reference to the following detailed description taken in connection with the accompanying drawing, in which thefigure 1s a diagrammatic representatlon of a por tion of a four-wire repeating circuit showparent, to amplify the ringing and the voice .currents from line section 10, 11. These repeaters are of the Well .tube type and comprise known discharge filaments '16,, 17, anodes 18, 19and control 21. hecircuit arrangement shown in connection' with-these amplifiers is of a type vnow well known in the art and a detailed description thereof is therefore not deemed necessary.

Located betweenthe amplifier l4:- and the JERSEY, AssIenoE' T0 WESTERN ELECTRIC and 15 arranged, as will be hereinafter ap- I electrodes 20 and incoming lines'ection 10, 11, isa wave filter" comprising series capacities 23 and shunt inductances 24., The elements of this wave filter should preferably have such preassigned values that the filter is of the socalled high pass type and suppresses all frequencies below the essential voice range, for example, it may suppress all frequencies below 200 cycles per second. The. values these elements should have to accomplish thisresult, may be readily obtained by reference to the United States patent to Campbell on wave filters No. 1,227,113 of May 22, 1917.

, Speech currents from line-section 10, 11 by freely transtransformers 26 and 27 will be mitted through the wave filter input transformers 28 and 29 pressed upon the input-circuit amplified thereby and after a second amplification by repeater 15 will be impressed upon the outgoing line section 12, 13. Element 25 is the usual gain adjusting poten- -and by the will be imof repeater 14 tiometerfor determining the amount of gain as connected between the secondary windmgs of transformers'26 and 27 and comprising an inductance 46 and a capacity 47 shunted by a resistance 48.

In order to transmit the telegraph cur rents around the wave filter and the re-" peaters, a by-path 30 may be provided from line wire by-path 3l-may be tingthe currents from line wire 13. is preferably connectedte each line wire, as shown,- by arconnection to a shunt path across each line section comprising inductances 33 and 34 and condensers 35 and 36. Inductance-s 33 {and 34 serve to prevent the speech "currents from being short-circuited by, this shunt path while condensers 35 and 36, aid in the-prevention of the inter ference between the twh grounded telegraph provided for transmitchannels 10, 30,.51-2' and 11, 31, 13. fieries ringing currents condensers 39, 40, 41 and 42 may also be provided to prevent'telegraph signals from one line wire from going through the associated transformer windings to the other line wire thereby producing interference. The by-paths 30 and 31shou1d preferably be provided with choke coils, such as 44 and 45 to prevent 'any of the speech currents from being by-passed around the repeater elements so that only currents of frequencies of the order of 12 cycles or less are efliciently transmitted therethrough; Since the wave filter disclosed is of the type designed to suppress all frequencies below the essentialspeech range, it follows that the wave filter will also suppress the telephone ringing currents, which ,are ge nerally of 135 cycles.

y re eater elements without destroying the e ciency of the wave filter to'suppress telegraph signals, is tofemploy a transformer 50 having a primarywinding incircuit with the primary windings of transformers 26 and 27 while the secondary winding is connected in series with the secondary windings of transformers 28 and 29. The-primary winding of transformer 50 should preferably be shunted by'a condenser 51 of such a value as in combination with the induc tance of the primary winding tocomprise an anti-resonant circuit for the frequency of the ringing curreiits, 135 cycles for example. With such an arrangement, transformer 50 will therefore be highly efiicient for the transmission of the ringing currents. The

value of condenser 51, however, will be such as tosubstantially short-circuit the primar winding of transformer 50 for the speec 1 currents.

It should also be noted that the trans- 10 to line wire 12,and a similar wire '11 to line Each'of the icy-paths 30 and 31 i euurplifying repeater, adjustable means be tween saidline and said repeater for attenuing directly upon said repeater currents of One way in which'the be impressed upon the 'for, a wave filter between said hue and said efliciently.

-The arrangement described above is intended merely as representative of the preferred embodiment. of the invention and it IS obvious that many other arrangements are-possible and will occur to those skilled in the art. I

' What is claimed is:

1. In combination, a transmission line, an

ating currents of a certain frequency range impressed on said repeater from said line, and a by-pass around said means for impressing other currents directly on said repeater without undergoing attenuation by said means.

2. in combination, a transmission line, an amplifying repeater, an electric wave filter between said line and said repeater for freely passing a band of frequencies while suppressing frequencies outside of said band, and a bypass around said filter for impressa frequency normally suppressed by said filterr 3. In combination, an incoming line, an

outgoing line, a wave filter therebetween, a transformer having its primary winding connected directly in said lncomin line an its secondary winding connected irectly in said outgoin line, and a condenser in shunt 7 to one of sai windings of such a value that combined with said winding an anti-resonant circuit is produced for a'fequency to be transmitted around said filter and through said transformer.

4. In combination, aline, a repeater theretransformer and having a second winding in 115 c1rcu1t with a winding of said second trans-- formen. p 1

5. In combination. a transmission'lina'a vacuum tube'repeater therein, anormally established connection from said repeater including a wave filter forselectively transmiting currents in said line-to said repeater, a normally established connection from said line to said repeater around said wave filter for by-passing certain .fre- 125 quencies .around said filter and for impressing them directly upon said repeater and a by-pass for currents of other frequencies around said filter and said repeater.

6. In combination, a wave filter, and a line to said I an anti-resonant circuit for path shunted around said filter comprising by-passing currents of a certain frequency around said filter.

7. In combination, a composite telephone and telegraph line, an amplifying repeater in said line, a Wave filter for suppressing the telegraph currents and the ringing currents in said line, a by-path around saidfilter and said repeater for selectively transmitting the telegraph currents, and a bypath around said filter for selectively transmitting directlyto the input ofsaid repeater the ringing currents employed in signaling over said line. i

8. A combined telephone and telegraph system, comprising an incoming line, an

outgoing line, a vacuum tube repeater there between, a wave filter in between said in coming line and said repeater, a by-path around said filter and said repeater for the telegraph currents in said incoming line, said path comprising an inductance of such a value as to prevent the transmission of speech curents through said path, atransformer for directly coupling said incoming line to said repeater independently of said wave filter, said transformer having one of its windings shunted by a condenser of such a value that combined with said winding an 'a nti-resonant circuit is formed for insuring that said transformer will transmit from said incoming line to said repeater currents of only the ringing frequencies found in said incoming line.

In Witness whereof, I hereunto subscribe my name this 29th day of JuneA. 1)., 1921.

RAY S. WILBUR. 

